Small form factor web browsing

ABSTRACT

A large web page is analyzed and partitioned into smaller sub-pages so that a user can navigate the web page on a small form factor device. The user can browse the sub-pages to find and read information in the content of the large web page. The partitioning can be performed at a web server, an edge server, at the small form factor device, or can be distributed across one or more such devices. The analysis leverages design habits of a web page author to extract a representation structure of an authored web page. The extracted representation structure includes high level structure using several markup language tag selection rules and low level structure using visual boundary detection in which visual units of the low level structure are provided by clustering markup language tags. User viewing habits can be learned to display favorite parts of a web page.

RELATED APPLICATIONS

This Patent is a Continuation of and claims benefit under 35 U.S.C. §120to U.S. patent application Ser. No. 10/306,729, filed on Nov. 27, 2002(hereinafter, the Parent). In turn, the Parent is related to U.S. patentapplication Ser. No. 10/177,803, filed on Jun. 21, 2002, titled “WebInformation Presentation Structure For Web Page Authoring”, which isincorporated herein in its entirety by reference (hereinafter, the FirstCitation). The Parent is also related to U.S. patent application Ser.No. 10/179,161, filed on Jun. 24, 2002, titled “Function-based ObjectModel for Web Page Display in a Mobile Device”, which is incorporatedherein in its entirety by reference (hereinafter, the Second Citation).The Parent is also related to U.S. patent application Ser. No.09/995,499, filed on Nov. 26, 2001, titled “Methods and Systems forAdaptive Delivery of Multimedia Contents”, which is incorporated hereinin its entirety by reference, and is hereinafter referred to as the“Related Patent” (hereinafter, the Third Citation). The Parent is alsorelated to U.S. patent application Ser. No. 09/893,335, filed on Jun.26, 2001, titled “Function-based Object Model for Use in WebSiteAdaptation”, which is incorporated herein in its entirety by reference,and is hereinafter referred to as the “Related Patent” (hereinafter, theFourth Citation).

TECHNICAL FIELD

This invention relates to adapting and rendering a web page for a smallform factor device.

BACKGROUND

The Internet can be browsed by small Internet devices such as handheldcomputers, personal digital assistants (PDAs) and smart phones. Thesesmall form factor devices have been used to leverage the capabilities ofthe Internet and provide users ubiquitous access to information. Despitethe proliferation of these devices, their usage for accessing today'sInternet is still largely constrained by their small form factors,particularly their small screen size and their limited inputcapabilities. Most of today's web content has been designed with desktopcomputers in mind. Web content is often contained in large web pageswhich do not fit into the small screens of these small form factordevices. The web browsing in such devices is like seeing a mountain in adistance from a telescope, where the user is required to manually scrollthe window to find and position the view correctly for readinginformation. This tedious and time-consuming browsing procedure haslargely limited the usefulness of small form factor devices. Thus,browsing a typical web page with these devices can be an unpleasantexperience.

To improve the browsing experience with a small form factor device, aweb page can be adapted by techniques that modify the web content tomeet both the client and the network capabilities. For instance, webobjects on a web page can be distilled to decrease the network andclient consumption, typically by discarding format information whichtends to detract from the designed aesthetics of the web page. A largeweb page can also be re-authored into its defined sections and sectionheaders, but there are few such specifications in typical web pages.

It is desirable to adapt a large web page for a small form factor devicesuch that the adaptation is fully automatic, the whole web page is takeninto consideration, and the resultant adapted page will be useable formost purposes. Additionally, it is desirable that the adaptation willleverage the web page authors' designing habits, preserve the visualimpression of the original web page, and provide an effective way toexpress and realize presentation design.

Accordingly, this invention arose out of concerns associated withproviding improved web page adaptation and re-authoring for small formfactor devices.

SUMMARY

In accordance with the described embodiments, web content is translatedfrom web content originally created for a large form factor device (e.g.a desktop computer) so that it can be viewed on a small form factordevice (e.g. a palm top computer). The translation analyzes the webcontent of a large web page, partitions the content of the large webpage into different sub-pages, learns user viewing habits oruser-inputted preferences, and displays the appropriate sub-pages basedon such learning or user-inputted preferences. By partitioning a largeweb page into sub-pages, a user can navigate the web page on a smallscreen of a small form factor device. The sub-pages are ranked byimportance according to an analysis of the content and according to theuser's preferences and needs. The user can jump between sub-pages tofind and read information in the content of the large web page. Thepartitioning can be performed at a web server, an edge server, at thesmall form factor client, or can be distributed across one or more suchdevices. Implementations include web page analysis that leverages designhabits of web page authors to extract a representation structure of aweb page. The web page analysis include extracting high level structureusing several markup language tag selection rules and then extractinglow level structure by visual boundary detection in which visual unitsof the low level structure are provided by clustering the leaf markuplanguage tags.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the various methods, apparatuses,computer programs, and systems of the present invention may be had byreference to the following detailed description when taken inconjunction with the accompanying drawings wherein:

FIG. 1 is a block diagram, in accordance with an implementation of thepresent invention, of a networked client/server system.

FIG. 2 is a flow diagram of a web page adaptation and presentmentprocess in accordance with one or more implementations, and in which theprocess has various steps, including a request for a web page from arequester, a provider that performs page analysis on the requested webpage including tag structure analysis, visual analysis, and clustering,and service of an index page or an auto-positioned sub-page by theprovider to the requestor.

FIG. 3 is a graph useful in an implementation for providing a dynamicthreshold for the determination of a header and/or a footer for a webpage.

FIG. 4 shows the result of an implementation in which a markup languagetag tree selection process is performed upon a web page so as topartition the web page into regions, including one header, one footer,one left side, one right side, and four body regions.

FIG. 5 shows the result of an implementation in which a visual boundarydetection process is performed upon a region of a fragment of a web pagethat includes a plurality of blocks each of which is projected on to anaxis in order to detect visual boundaries in the region of the web page.

FIG. 6 shows a sequence of illustrations with respect to the regions ofthe fragment of the web page seen in FIG. 5 that is subjected to aclustering process based upon its markup language tree tag sequence, andin which groups of nodes are formed in order to determine visual unitsfor detecting boundaries for the region of the fragment of the web page.

FIG. 7 is a diagram illustrating an overview of an analysis andpartitioning of a web page, including processes for markup language tagtree selection, clustering, and visual analysis, where the overview isuseful in understanding aspects of one or more describedimplementations.

FIGS. 8 a and 8 b are, respectively, a block diagram of an index pagewith corresponding sub-pages and an example of a web page expressed asan index page that is split into smaller sub-pages for separate viewing.

FIG. 9 is a diagram of an exemplary web page to which anauto-positioning process has been applied for prioritized viewing ofsub-pages thereof on a small form factor device in accordance withvarious implementations.

FIG. 10 is a block diagram of an exemplary computer environment in whichvarious implementations can be practiced.

DETAILED DESCRIPTION

Overview of Page Analysis and Presentation For Small Form Factor Devices

This patent presents a web page adaptation method of page partitioningfor browsing on a small form factor device. The web page adaptationmethod includes processes for analyzing a web page to obtain itsstructure and then splitting up the web page. In the analysis process, ahierarchy of regions is created to represent the semantic and visualstructure of the web page. According to this hierarchy, and the screensize of the small form factor device, appropriate blocks are selected assub-pages.

After sub-page generation, an image index page is created to assist auser in navigating the web page. The image index page is marked withsub-pages, each of which is made up of one of more of the regions. Whenbrowsing, the user will first view a thumbnail rendering of the imageindex page. Then, in a bi-level browsing convention, the user can clickon one of the marked sub-pages on the thumbnail of the image index pageto go to the desired sub-page. Alternatively, the user's historicalbrowsing habits for the web and for particular web pages can be analyzedto prioritize the first sub-page that the user will see when requestinga web page.

Turning to the drawings, wherein like reference numerals refer to likeelements, implementations of the invention are illustrated in a generalnetwork environment. Although not required, implementations aredescribed in the general context of computer-executable instructions,such as program modules, being executed by a computer or like device,which, for example, may take the form of a personal computer (PC), aworkstation, a portable computer, a server, a plurality of processors, amainframe computer, a wireless communications base station, and smallform factor devices such as hand-held communications devices (e.g. acellular telephone, a palm top computer, a streamed media player, aset-top box, etc.).

General Network Structure

FIG. 1 shows a client/server network system and environment, inaccordance with an implementation, for transreceiving data over wired orwireless IP channels and networks. Generally, the system includes one ormore p) network server computers 102, and one or more (q) network clientcomputers 104. The computers communicate with each other over a datacommunications network, which in FIG. 1 includes a wired and/or wirelessnetwork 106. The data communications network might also include theInternet or local-area networks and private wide-area networks. Networkserver computers 102 and network client computers 104 communicate withone another via any of a wide variety of known protocols, such as theTransmission Control Protocol (TCP) or User Datagram Protocol (UDP).Each of the p network server computers 102 and the q network clientcomputers 104 can include a codec for performing coding and decoding fordata that is respectively transmitted and received.

Network server computers 102 have access to data including streamingmedia content in the form of different media streams. These mediastreams can be individual media streams (e.g., audio, video, graphical,etc.), or alternatively composite media streams including multiple suchindividual streams. Some of the data can be stored as files 108 in adatabase or other file storage system, while other data 110 might besupplied to the network server computer 102 on a “live” basis from otherdata source components through dedicated communications channels orthrough the Internet itself. The data received from network servercomputers 102 are rendered at the network client computers 104.

As shown in FIG. 1, the network system in accordance with animplementation of the invention includes network server computer(s) 102from which a plurality of media streams are available. In some cases,the media streams are actually stored by network server computer(s) 102.In other cases, network server computers) 102 obtain the media streamsfrom other network sources or devices. The system also includes networkclient computer(s) 104. Generally, the network client computer(s) 104are responsive to user input to request media streams corresponding toselected content. In response to a request for a media streamcorresponding to the content, network server computer(s) 102 streams therequested media streams to the network client computer 104. The networkclient computer 104 renders the data streams to produce a presentation.

FIG. 2 shows an implementation for a process in which a requestor 200requests a web page at block 202. At block 204, the request for the webpage is relayed to a provider 250. Blocks 204, 224, and 230 in FIG. 2are representative of transmissions over one of more wired and/orwireless networks. Requestor 200 can be a computing environment similarto network client computer 104 in FIG. 1 and provider 250 can be acomputing environment similar to network server computer 102 in FIG. 1.Provider 250 receives the request for the web page at block 206 andqueries whether the web page is annotated at block 208. If the web pageis annotated, the process moves to a block 222 which is discussed below.Otherwise, the process moved to block 210 where web page analysisbegins. A markup language tree tag selection process is performed atblock 210 to extract high level structure of the web page using severalmarkup language tag selection rules. Implementations of the markuplanguage tree tag selection process are discussed below in reference toFIGS. 3-4 and 7. After tag selection at block 210, the process moves toblock 212 where further web page analysis is conducted. In particular,block 212 extracts low level structure of the web page by visualboundary detection at block 214 in which visual units of the low levelstructure are provided by clustering at block 216. After blocks 214 and216 are performed sufficient to extract the low level structure of theweb page, the process moves to block 218 where the web page is segmentedinto sub-pages and then to block 220 where the segmented web page isannotated for an image index page and sub-pages thereof. The annotation,which is a kind of re-authoring of the originally requested web page, isstored for future use at block 222. Provider 250 then serves requester200 at a transmission at block 224 of the image index page of therequested web page.

Requestor 200 receives the transmission at block 226 at which point adisplay of the image index page can be made by requestor 200, such asupon a small screen. The image index page can assist the user ofrequestor 200 in navigating the requested web page. The image index pageis a thumbnail view that is marked with one or more sub-pages. At block232, the user inputs to requester 200. The user's input is examined atblock 234.

The user can input one of the sub-pages that the user desires to view ina larger display, such as by tapping upon a touch-sensitive displayscreen of requestor 200 at the location of the desired sub-page as ameans of input. If the user inputs a request for a specific sub-page,block 234 moves control to block 204 where the request for the sub-pageis transmitted to provider 250. The user's request for the sub-page isreceived at block 206. The prior annotation of the requested web page isacknowledged at the query of block 208 such that control moves to block222 to retrieve the requested sub-page from storage and to transmit thesame back to requester 200 at block 230, Requestor 200 receives anddisplays the requested sub-page at block 232, which display allows theuser to input further requests at block 234.

If a sub-page is displayed at block 232 and the user inputs a request todisplay the thumbnail view of the image index page, control returns toblock 226 to display the thumbnail view. In this case, the image indexpage can be stored locally at requester 200. Alternatively, requester200 can input a request for the same or a different web page to provider250, in which case control moves to block 202 for a repetition of theforegoing.

Obtaining the High Level Structure of a Web Page

A web page, especially a large one designed for viewing on a desktop PC,can be logically partitioned into regions, each representing a unit ofrelatively independent information that can be managed and displayedseparately. It is possible that a logical region is complex and containssmaller logical blocks, thus forming a logical region hierarchy. Such alogical region hierarchy represents the semantic structure of a webpage. Obtaining the structure requires understanding or analysis of theweb page. To assist the computational environment in assessing thesemantic of web pages, the structure of the web page can be obtained byleveraging the authors' designing habits.

When designing a web page, especially a large web page, the authorusually partitions the web page into several high level regions to setup a scaffold-like structure of the web page. To produce the scaffold,the author usually uses markup language tags for layout purposes at thehigh level regions of the web page. Therefore, analyzing web page'smarkup language tag tree can provide enough information to detect thehigh level structure or regions of the web page. For example, the authorwould consider whether the page should contain the high level regions ofa header, a footer, and side bars. These regions form the periphery ofthe web page and any body regions, where are also high level regions,are surrounded by the periphery regions. The author may also considerhow many topics should appear in the body regions of the web page. Forexample, the Hyper Text Markup Language (HTML) tag tree of a web pagecan be used to detect its high level regions.

After setting up the high level regions of the web page, the authorfills each region with desired content. Inside the region, if thereshould be further partitioning, the author usually provides visualseparators to tell the reader the boundaries of the content in the webpage. Repeating patterns in the region suggest that the objects in theweb page that correspond to each pattern probably represent a basicsemantic unit.

In this patent, implementations of a web page analysis method focus uponthe authoring design habits. The method first analyzes the markuplanguage tag tree structure in order to derive therefrom the high levelstructures or regions of the web page. These high level regions includea header, a footer, left and right side bars, and one of more bodyregions. Within each high level structure, a pattern detection algorithmcan be used to find one or more basic semantic units. The basic semanticunits are then projected to find the visual boundaries of the high levelstructures. The finding of the visual boundaries produces one or morelow level structures for each of the high level structures. The high andlow level structure information can then be stored using an annotationmechanism. The stored information can be retrieved and used fordisplaying the web page on small form factor devices.

From the layout's perspective, each web page can contain one or more offive regions: header, footer, left side bar, right side bar, and one ormore body regions. The header and footer regions are typically shorterthan the other regions. The header region is located at the top of theweb page and the footer region is located at the bottom of the web page.Side bar regions are tall and thin and located at the left or right sideof the web page. The body regions are typically neither as short as theheader or footer regions nor as thin as the side bar regions. Rather,the body regions are usually located at the center part of the web pageso as to attract most of the browsing user's attention.

Based on the layout information in the markup language tree tagstructure, the heuristics for the five regions can be found (e.g.header, footer, left side bar, right side bar, and body regions).

Deriving the Header and Footer Regions

Generally speaking, a header region should appear at the top of thepage. To do so, the upper N pixels of the web page can be defined as theheader region. All of the tree tags falling inside the header regionwholly are considered to be header blocks.

The shape of a tag tree region is also taken into account. It ispreferable that the shorter tag tree regions have a larger possibilityof being placed into the header region. In other words, the shorter theregion—the larger the value of N. As illustrated in FIG. 3, a dynamicthreshold for the header region can be determined asN=base_threshold+F(Height/Width), where F(x)=a/(b*x+c), x=Height/Width,and base_threshold, a, b and c are constants. It is preferred, althoughoptional, that the following value set be used: base_threshold=160,a=40, b=20, and c=1. The footer region is derived similar to that headerregion, except that the bottom N pixels of the web page are defined asthe footer region.

Deriving the Left and Right Side Bar Regions

A heuristic can be set that any tree tags that fall into the left fourthpart of the web page will be considered to be in the left side barregion, where the right fourth corresponds to the right side bar region.Other partitioning besides one third can also be used for the derivationof the opposing side bar regions, which need not be the same size.

The foregoing derivation does not take the shape of the opposing sidebar regions into account because they may contains several small regionswhich are not thin when examining them alone.

Deriving the Body Regions

The regions that do not match the rules for the header, footer and sidebar regions are considered to be body regions. The derivation of thebody regions, however, can be complex. For example, in a web page, a<BODY> tag can contain a <CENTER> tag as its only child (e.g. the authoruses the <CENTER> tag to align the whole page to the middle). When usingthe rules for the derivation of the header/footer and the side barregions, it can be concluded that the region of the <CENTER> tag is notheader, footer or sidebar. Neither the <BODY> tag nor the <CENTER> tagshould be considered to be a body region because a tag that represents arelatively large region will likely contain several high level structureregions. As such, it is desirable to detect each tag that is arelatively large region and then split or divide the tag into smallerblocks.

When tags are associated with relatively large regions, the tag can besplit up into smaller blocks, unless the tag matches one or more of thefollowing rules:

-   -   (i) If a tag corresponds to a header or footer region, it does        not need to be split;    -   (ii) If a tag corresponds to a side bar region, it does not need        to be split;    -   (iii) If a tag's width or height is smaller than a base line        threshold (see FIG. 3, supra), it does not need to be split.

In rule (iii), above, it is preferable to vary the base threshold (e.g.see FIG. 3) for width and height for different kinds of web pages. Forexample, for the multi-subject web pages typical of a “home page” for aweb site used by a large number of users (e.g. msn.com, yahoo.com,aol.com, etc.), it is preferable, although optional, to use 240 pixelsfor the width and to use 150 pixels for the height.

FIG. 4 shows a web page before and after an implementation of the markuplanguage tree tag selection process that uses formatting information inthe markup language (e.g. HTML) of the web page. The result of the treetag selection process is the detection of several regions as depicted inrectangular blocks, including one header region at the top of the webpage, one footer region at the bottom of the web page, one left side barregion, one right side bar region, and four (4) body regions asindicated by reference numerals 1 through 4.

Obtaining the Low Level Structure of a Web Page

In FIG. 4, the second and third body regions have low level structures,but if they are split by their respective tag tree structures, differentresults are produced. For the second region, splitting it by its tagtree structure will produce a favorable result since its tag treestructure matches its semantic structure. The third region (e.g. the<TABLE> tag) is composed of three columns of content from a semanticpoint of view. The tag tree structure selection algorithm, however, canpartition the region only by the row or by the cell. As such, once thehigh level structure of the web page has been derived (e.g. theregions), the web page can be farther analyzed to derive there from itslow level structure (e.g. one or more blocks within each region).

At the middle level, a web page author usually provides visualboundaries to inform a reader of the structure of the web page. Thesevisual boundaries can be used to detect the low level structures of theweb page. There are two kinds of visual boundaries—explicit andimplicit. Some markup language tags, such as the HTML tags <HR> andbordered <DIV>, provide explicit indication of boundaries. Sometimes,the author just uses blank areas in the web page to indicate boundary.These boundaries are implicit.

Explicit Boundary Detection

Explicit boundaries can be detected by analyzing the properties of thetag tree structures of a web page. The <HR> tag is a tag tree structurethat is a boundary itself. Some tags, such as <TABLE>, <TD> and <DIV>,have border properties. When their border properties are set, there areboundaries at corresponding borders. Besides these two kind of explicitboundaries, there are still boundaries indicated by images. An exampleof explicit boundaries can be seen in the third body region depicted inFIG. 4, which is also seen at reference numeral 706 in FIG. 7. In thesefigures, the horizontal line 703 a at the top of the image is an <HR>tag. The two vertical lines 703 b, 703 c at the middle part of the imageare <IMG> tags in table cells. Stated otherwise, there are four <TD>tags involved, including two for the content row and two more for the“more xxx . . . ” row that is seen in the third body region.

From the clues on explicit boundaries, the third body region depicted inFIG. 4 can be further partitioned into four (4) blocks. The partitioningof reference numeral 706 in FIG. 7 into four (4) blocks can be seen witha first block at reference numeral 708 that contains three icons:‘Microsoft NET’, ‘Microsoft Windows’, and ‘Microsoft Office’. Thesethree icons are placed in one block because they are actually in asingle image. The rest of reference numeral 706 in FIG. 7 is dividedinto three (3) columns which contain detailed information aboutMicrosoft. NET™, Microsoft Windows®, Microsoft Office®, respectively.FIG. 7 shows reference numeral 703 a at the top of the image which is an<HR> tag representing a thin line. FIG. 7 also shows boundary images atreference numerals 703 b and 703 c which are <TD> tags, each beingrepresented as a thin line. In sub-block 706 b, the <HR> tag ofreference numeral 703 a and the boundary images at reference numerals703 b and 703 c are discarded since they are boundaries.

Implicit Boundary Detection

The implicit boundaries are blank areas created intentionally by theauthors to indicate content group borders. They cannot be detecteddirectly by analyzing the tag tree structure properties. Since they areblank, a projection based method can be used to detect them.

The whole web page or a part of the web page is composed of a set ofcontent objects, as was disclosed in each of the First, Second, Third,and Fourth Citations. Each content object occupies a rectangular.Projecting these rectangles to one axis that is perpendicular to anotheraxis will generate a chart indicating the number of objects at thedirection of each point on the axis (e.g. projecting content objectrectangles to the X or Y axis, as was disclosed in the First Citation).A point with a zero projection value indicates a possible implicitboundary which is seen on the web page as being a blank area or a gap.

In one implementation, the projecting of the rectangular shapes servesthe goal of identifying blank areas in the high level structure (e.g.the regions) of the web page. To do so, one or more functions of theobjects in each region are analyzed on the basis of a layout structureof each function. This analysis is performed by configuring eachfunction into a rectangle. Each rectangle is then projected normallyonto each of perpendicular axes (e.g. X and Y axes). One or moreseparators in each region can then be determined as a function of thesum of the projections on each axis, where each separator projectsnormal to one of the axes.

In another implementation, the blank areas in each region can be definedby processing the markup language tag tree defining each region toidentify therein multiple different objects. Each individual object hasone or more properties relating its functions. Functions of theindividual objects can then be analyzed. This analysis is conducted bygrouping one or more objects associated with the region into a shapethat contains at least one function. Each shape is then separated fromthe other shapes by a separator. Each shape is a rectangle having sidesparallel or normal to that of the other rectangles and to theseparators. Blanks are then inserted between the shapes. Each shape isthen projected normal to two perpendicular axes (e.g. X and Y axes).Each projection along each axis is then quantified. The separators,which represent implicitly determined blank space in the region, canthen be identified as being perpendicular to those points along eachsection of each axis where the quantity of the projections is less thana predetermined threshold.

FIG. 5 shows a fragment 504 a from a Web page. Fragment 504 a can befurther divided by a transition 506 to a column form 504 b, which can bebetter seen by a transition 508 into a sub-block 504 c. Sub-block 504 cis a <TD> tag tree structure. The <TD> tag contains four <DIV> tagsindicated by the bounding rectangles in sub-block 504 c. According tothe tag tree structure, the <TD> tag can be further partitioned intofour parts, each corresponding to one <DIV> tag. From the semanticinformation, however, it can be seen that the fragment 504 a should bedivided into two blocks each contains two sub-blocks —one of which is504 c.

In one implementation, the effective layout information of the four<DIV> tags in the tag tree structure of sub-block 504 b are collected bya clustering routine that is discussed below with respect to FIG. 6 andtransition 707 seen in FIG. 7. The collected information for the four<DIV> tags is represented by four (4) rectangular areas that can then beprojected to the Y axis. As seen in FIG. 5 after transition 508, threegaps are seen after projecting the four (4) rectangular areas. It ispreferable, although optional, to select the largest gap—which is themiddle gap.

Using the explicit and implicit boundary detection processes discussedabove, probable visual boundaries can be detected in the web page orfragments thereof. All probable visual boundaries, however, are notproper boundaries. Rather, it is preferable to apply boundary selectionrules to select proper boundaries from among the probable visualboundaries that were determined by the explicit and implicit boundarydetection processes. These preferred rules are:

-   -   a. For the implicit boundaries, the widest gap(s) is/are        selected. The widest gap has the longest segment along the Y        axis of contiguous points that have a zero projection value;    -   b. Since a region is to be partitioned into several smaller        blocks, only those explicit boundaries that spread from one side        of the region to the other side are eligible. For example, the        two vertical lines in FIG. 7, indicated by two reference        numerals 703 b and 703 c, will not be chosen when considering        the whole third body region;    -   c. If implicit boundaries and explicit boundaries are both        present, explicit boundaries will be chosen first.

Clustering

Because the implicit boundary detection process discussed above is basedon projecting the detected visual units to the X or Y axis to find thegaps, it can be sensitive with the input visual units. If the visualunits are too big, it will probably lose some useful gaps. If the visualunits are too small, there will be too many small gaps. In order tomaximize the useful gaps while minimizing the gaps that are noise (e.g.too small to be easily discerned), a pattern recognition process can beused to cluster the leaf markup language tags (e.g. leaf HTML tags) intosmall groups and produce the visual units. In illustration of thepattern recognition process, FIG. 6 shows a sub-block 504 c that wasdetermined from the visual boundary detection processes discussed above.Sub-block 504 c corresponds to the fourth (4^(th)) DIV tag in block 505b. A transition 602 seen in FIG. 6 illustrates the identification of thetag tree structure of sub-block 504 c.

Sub-block 504 c in FIG. 6 contains a tag sequence 604 which is“<A><BR><A><BR><A><BR><BR>”. It can be determined that the “<A><BR>” isthe most frequent pattern in the tag sequence 604. According to it, each“<A><BR>” can be formed into three small groups of tag sequences seen atreference numeral 612. Then, the three small groups 612 can be groupedinto a virtual node VN 608 since it is a list. Now the detail structureinside a DIV 606 changes into the tree structure form shown in themid-section of FIG. 6. The virtual node VN 608 is preferred to become avisual unit for implicit boundary detection (e.g. by projecting thecorresponding rectangular area) since a last BR 610 represents an emptyline. For the four blocks depicted after transition 508 in FIG. 5, ifthe second block corresponding to the second DIV tag was selected as thevisual unit, the gap under it would not be wide enough to be preferredbecause the DIV tag contains an extra BR which will extend the height ofthe second block, similar to that seen in the tag tree structuredepicted in FIG. 6.

An implementation of a clustering process 616 is depicted in the latterportion of FIG. 6 after transition 614. At block 620 of clusteringprocess 616, a collection is made of the basic nodes (e.g. a collectionof all of the atomic nodes in the HTML Document Object Model (DOM) tree,as was disclosed in the Second Citation.). The collected basic nodes arethen arranged in the order of the markup language document sequence(e.g. the HTML document sequence). The basic nodes include all the leaftags. Some special tags are also basic nodes regardless of whether theyare a leaf node or not. For example in the HTML markup language, the tag<A> should always be a basic node since it denotes a hyperlink. Otherspecial tags include <MARQUEE>, <SELECT>, <MAP>, etc. Because tag andtext can become a tag's child at the same time in HTML, collecting leaftags only will probably leave the text nodes out. So the text nodes arealso basic nodes. If a text node is the only child of a tag, the tagwill be selected as the atomic node.

After the basic nodes have been collected and ordered at block 620,clustering process 616 moves to block 622 where the basic nodes areclassified into categories based upon text font, size, color, and tagproperties. The basic nodes in the same category will be represented bya symbol thus changing the node sequence into a symbol string.

After block 622 has transformed the collection of basic nodes into asymbol string, clustering process 616 moves to block 624 where all thepossible patterns are detected (e.g. sub-strings of the symbol string).The detected patterns are counted as to their frequency in the symbolstring (e.g. the number of times that the sub-string appears in thesymbol string). Among the patterns with highest frequency, the longestpattern is selected. The longest pattern is then grouped into a newsymbol if its length is bigger than 1. If the length is equal to 1,clustering process 616 moves to block 626 where an attempt will be madeto merge adjacent symbols. If no merge can occurs, clustering process616 return to block 624 where the pattern with next highest frequencywill be selected. Clustering process 616 can be applied on the newlycreated string until the highest frequency is below a predeterminedthreshold. Each non-blank symbol in the last string represents a visualunit for boundary detection. The blank symbol includes the <BR> tag,space characters, a blank <TD> tag (e.g. a <TD> tag that contains spacecharacters only), a blank <MAP> tag, a blank <SCRIPT> tag, etc.

An exemplary overview of the foregoing tag structure analysis,clustering, and visual analysis for a fragment 706 of a web page 702 ais seen by a transition sequence depicted in FIG. 7. Following a markuplanguage tag tree structure analysis, web page 702 a can be representedas a web page 702 b that is divided into regions that include a header,a footer, left and right side bars, and four body regions 704, 705, 706,and 710. Body region 706 can be divided into the three (3) columns 706a, 706 b, and 706 c. Each column contains low level structureinformation respectively corresponding to the icon in a block 708 (e.g.Microsoft .NET™, Microsoft Windows®, Microsoft Office®). As discussedabove, three lines divide the three columns, including one line for thereference numeral 703 a at the top of the image, and two lines for thetwo reference numerals 703 b and 703 c.

A clustering process 707 (e.g. an example of which is also seen asprocess 616 in FIG. 6) is performed to derive sub-blocks from web pagefragment 706. To do so, basic nodes are collected, organized, andclassified. Markup language tag patterns are detected and the detectedpatterns are merged where desirable and/or in accordance withpredetermined rules. The result of the clustering process 707 is foursub-blocks in each of the three columns 706 a, 706 b, and 706 c.Clustering process 707 derives from column 706 a the sub-blocks 706 a 1,706 a 2, 706 a 3, and 706 a 4. Sub-blocks 706 b 1, 706 b 2, 706 b 3, and706 b 4 are derived from columns 706 b by clustering process 707.Clustering process 707 also derives from column 706 c the sub-blocks 706c 1, 706 c 2, 706 c 3, and 706 c 4. Each sub-block is a rectangular areathat can be projected to perpendicular X and Y axes. Segments alongthese axes that are composed of points having a zero projection valuerepresent blank areas of the web page that are eligible to be impliedvisual boundaries. The longest segments, as was discussed above withrespect to FIGS. 5-6, are preferred as the implicitly determinedboundaries in the web page.

A visual analysis process 712, which can be performed after clusteringprocess 707, uses explicit and implicit boundary detection rules tolocate boundaries for the blocks seen at reference numerals 703 a, 703b, and 703 c for fragment 706 of web page 702 a. The boundary indicatedby reference numeral 714 can also be derived by explicit and implicitboundary detection rules.

Storage of Web Page Analysis Results

The processes indicated in FIG. 7 are repeated for all of web page 702 auntil a complete analysis thereof has been made. After the analysis, aresult can be stored for future use. If each logical block correspondsto one tag, which is the case for the output of the tag selectionprocess set forth above, a special attribute can be added to each tag toindicate whether it is a logical block. For example, “<P block=“true”> .. . </P>” means that all the content inside this tag (including Pitself) constitutes a logical block. However, as indicated in the abovediscussion of visual boundary detection (explicit and implicit) andclustering processes, there are multi-level logical blocks and eachlogical block does not correspond to one tag. In this case, a logicalblock hierarchy structure is desirable to store the analysis result. Anannotation mechanism can be used to store the logical block hierarchystructure of a web page into an external markup language file, such asan XML file where the corresponding place of a block in the originalHTML document is indicated by XPath and XPointer. Such an annotationmechanism can be used to store the analysis result into a separate file.

By storing the structure information of a web page in a separateexternal markup language file, two advantages are gained. First, theseparate file represents the logical block hierarchy structure withoutmodifying the original markup language document. Second, for a set ofweb pages with the same structure template, a single structure file canbe used for each page in the set of web pages.

Summary of Tag Selection, Clustering and Visual Boundary DetectionProcesses

The structure of a web page can be obtained by the above described tagtree selection, clustering, and visual boundary detection processes. Inthat the semantic structure of a web page is difficult to derive,typical design habits of authors can be used to extract therepresentation structure of a web page in an analysis process thatincludes two steps. The first step extracts high level structureinformation about the web page using several markup language tag treeselection rules. The second step extracts low level structureinformation about the web page by visual boundary detection, in whichthe visual units are provided by the clustering process.

Re-Authoring Web Pages

After obtaining and storing the web page structure, adaptation can beconducted according to the clues provided by structure. For a large webpage in terms of layout, viewing it on small form factor devicesrequires extensive scrolling, which makes the browsing experience moredifficult. One implementation involves adapting a large web page toshrink it so that it will fit in the small screen of a small form factordevice (e.g. a mobile handheld device) by splitting it into smallersub-pages. This implementation is discussed below.

Web Page Splitting Schemes

There are various ways of splitting a web page, which can becharacterized into two basic actions: single-subject splitting andmulti-subject splitting. Single-subject splitting splits the whole webpage into several sub-pages and connects the sub-pages with next/backhyperlinks. The result of single-subject splitting is a double linklist. While browsing, the user has to access sub-pages one by one in thesequence of the link list. Multi-subject splitting generates a localindex page in addition to the sub-pages. The local index page containshyperlinks pointing to each sub-page. So the result of multi-subjectsplitting is a star-like structure. While browsing, the user willreceive the local index page first. Then the user can access eachsub-page through the hyperlinks in the index page. Thus, themulti-subject splitting introduces a bi-level browsing experience. Themulti-subject spitting technique is preferred, although optional, inthat it cannot be readily determined whether a web page issingle-subject or multi-subject.

An example illustrating multi-subject splitting is seen in FIG. 8 awhere a thumbnail image of a local index page has been generated from amulti-subject web page that has been split into sub-pages, where thesub-pages are generated as the images seen in P1 through Pn.Multi-subject splitting includes sub-page generation and local indexpage generation which are discussed below.

Sub-Page Generation

A prerequisite of sub-page generation is selecting appropriate logicalblocks (e.g. regions) from the web page structure. For small form factordevices, the appropriate logical block should be small enough to fitinto the small screen of the device. Since web browsing typicallyinvolves vertical scrolling, in that horizontal scrolling is disfavored,the width of a selected logical block should be smaller than or equal tothe small screen of the device while its height can be larger. However,there are some logical blocks that have a small height hut also have alarge width. Splitting these logical blocks can produce too manysub-blocks. Alternatively, the logical block can be a header or footerregion which cannot be made smaller as to its width dimension. So, theshort blocks should be selected if their heights are smaller than thescreen height. Thus the criterion becomes that the block height shouldbe less than or equal to the screen height or block width should be lessthan or equal to the screen width.

After selecting the appropriate logical blocks, their correspondingmarkup language contents should be extracted from the original web pageand put in the newly created sub-pages. The XPath and XPointer tags canbe used to store the correspondence between the logical block and thecorresponding markup language content. According to these clues, thecontent of the logical block can be extracted.

The extracted content cannot be put into a sub-page directly because oftwo problems: the style information and the hyperlinks.

Style Extraction

A markup language standard can permit a web page author to specify thecontent style. For example, the HTML standard can permit a web pageauthor to use a Cascading Style Sheet (CSS) and style inheritance tospecify the content style. The CSS allows authors to define the stylesof tag, tag class or tag instance. Style inheritance allows author tospecify a node's style at one of its ancestor nodes. Extracting theblock content may probably lose some style information because the styleinformation from the CSS and the style inheritance is not located withthe content.

In order to keep the block similar with the original web page, the styleinformation can be collected. For the CSS case, since the CSS is usuallyspecified in the <HEADER> tag using <STYLE> or <LINK>, the <HEADER>section of the original web page can be simply copied to each sub-page.

For the style inheritance case, a trace can be made along the parentlink of the target node and a collection can then be made of all of thestyle information of each parent tag. The style information fromancestor nodes and the node itself are merged as child nodes, withhigher priority over ancestor nodes.

Hyperlinks

Web page use internal hyperlinks to assist the user in locating contentinside the web page. In these web pages, authors use <A id=“id1”> . . .</A> to specify a place in the web page. Then <A href=“#id1”> . . . </A>can be used as the pointer to the specified place. When clicking on theinternal hyperlinks, the browser will scroll to the specified place.

If the web page is split into several sub-pages, the place specifier andthe pointer may appear in different sub-pages. For example, <A id=“id1”>. . . </A> may appear in t1.htm while <A href=“#id1”> . . . </A> appearsin t2.htm. In this case, the browser will fail to bring the user tot1.htm on clicking the pointer in t2.htm if the pointer <A> is keptunchanged. The solution is to change the pointer in t2.htm to <A href=“. . . t1.htm#id1”>. </A>. A module, routine, or process that splits theweb page can be made to search the internal hyperlinks and change thepointer to an appropriate form.

The sub-page can include both ‘inter’ and ‘intra’ hyperlinks. Eachsub-page can include one or more hyperlinks that link to anotherlocation within the sub-page (e.g. an ‘intra-sub-page’ hyperlink). Eachsub-page can also include one or more hyperlinks that link to anothersub-page (e.g. an ‘inter-sub-page’ hyperlink).

Another problem concerns the resolution of relative hyperlinks. A webpage author can specify absolute hyperlinks or relative hyperlinks in<A> and <AREA>. The browser resolves the relative hyperlinks to absoluteones according to a base URL of the web page. The default base URL isthe URL of the web page. An author, however, can override the base URLusing a <BASE> tag. The <BASE> tag resides in the <HEADER> section,which becomes another reason for copying the <HEADER> section to eachsub-page.

The image maps (e.g. the <MAP> tag) also imposes some difficulties onsub-page generation, since an <IMG> tag can reference a <MAP> defined atany place in the original web page. Preserving the image map can be doneby searching the referenced <MAP> across the original page and addingits content to the sub-page where the <IMG> resides.

Local Index Page Generation

Because the multi-subject splitting scheme is preferred, the local indexpage should be generated after all the sub-pages have been generated. Inthe local index page, the central problem is to generate properhyperlinks to the sub-pages.

Generating the ‘href’ values can be based on a sub-page naming strategy.Each sub-page can be named in the form of origin_xxx.htm, where the‘origin’ denotes the name of the original web page and ‘xxx’ denotes anumber. For example, the first sub-page of default.htm isdefault_(—)1htm, the second one is default_(—)2.htm, and so on.

Besides the ‘href’ values, content is needed to represent the hyperlinks(e.g. the content between <A> and </A>). If the content is in text, asummarization utility can be run against each sub-page to produce thecontent text. Image content hyperlinks are preferred for sub-pages thatmainly contain images.

As seen in FIG. 8 b, a thumbnail image 800 is generated for an originalweb page. To assist the user of a small form factor device having colordisplay capabilities, it is preferable to mark the sub-pages withdifferent colors. An <IMAGE> tag can be used to reference the thumbnailimage and a corresponding <MAP> tag can be placed in the local indexpage. While browsing the local index page, the user can select or‘click’ on a specific colored sub-page of the thumbnail image to go tothe selected corresponding sub-page. As seen in FIG. 8 b, sub-pages 803,805, 807, and 809 have been generated from the original web page and aredelineated on the thumbnail image 800 of the local index page to bereadily selected for bi-level browsing by a user. For example, the usercan use the up/down/left/right button on a user interface (UI) of asmall form factor device to move the window display thereof between thesub-pages depicted on the thumbnail image 800 of the local index page.Once selected from the small icon of the entire web page, the selecteddisplay will zoom to a larger display of the selected sub-page.

A certain amount of processing is required in order to accomplish theanalysis and partitioning of each web page requested by a small formfactor device. If the latter is not powerful enough, the analysis andpartitioning can be performed at the corresponding proxy server oranother web server or an edge server. Alternatively, the analysis andpartitioning can be distributed across one or more such devices. Forexample, the analysis and partitioning of each web page can be performedby an editor, by the client device or by a third party service provider:

-   -   (i) A web page editor (e.g. FRONTPAGE® software from the        Microsoft Corporation of Redmond, Wash., USA) can add special        attributes to mark up language tags to indicate sub-pages. A        browser (INTERNET EXPLORER® software from the Microsoft        Corporation of Redmond, Wash., USA) on a small form factor        device can recognize these attributes and provide intelligent        positioning.    -   (ii) If the web page editor does not provide the special        attributes, a third party web service can perform page layout        analysis on the fly and add the layout information as a service.    -   (iii) If the client device is powerful enough, it can perform        page layout analysis by itself and provide this capability.

Prioritization Of The Regions

Some simple text analysis and heuristic rules can be used to identifywhich region contains more important information to a browsing user. Thebrowser may start by displaying a sub-page of an index page that hasbeen determined to have the most importance. The sub-pages can beprioritized according to their importance when assisting the user tonavigate them. To illustrate this, FIG. 9 shows an example of contentadaptation from a desktop display to a display that can be rendered bybrowsing software for a small form factor device (e.g. Microsoft® PocketPC software provided by the Microsoft Corporation of Redmond, Wash.,USA). In the adaptation depicted in FIG. 9, a thumbnail image 800 of anindex page contains a plurality of icons. Each icon represents asub-page of the original web page, including four (4) sub-pages thathave been determined to be of interest, in the particular orderindicated, to a user.

Learning a User's Browsing Pattern to Enhance Device Performance

-   -   A. If the user often follows a particular path or always wants        to see a particular sub-page of a web page (e.g. a stock quote        in the www.MSN.com home page), such knowledge can be acquired by        a passive learning algorithm. Then, the next time when the user        browses to visit the same home page again, the browser will have        been trained to immediate start with that sub-page.    -   B. Keywords from each sub-page can be extracted and matched with        user's previously specified interests. When the user browses a        web page, the browser can position directly to the sub-page        which the user is most interested in.

On a small form factor device, the browser software can passively tracka user's browsing behaviour to learn the user's interests. Whenbrowsing, the browser software will prioritize one or more sub-pages ofa web page using the methods described above. Then, the browser softwarewill direct a display of the derived most important sub-page of the webpage. An example of the result of active and passive learned browsingbehaviour is seen in FIG. 9. In FIG. 9, the browser software learns thatthe user is most interested in the mid-right side of the index page. Sowhen the user browses the web page, the browser software goes to thatsub-page first and positions the sub-page properly inside the screen.The browser software can also learn secondary interests of the user.When so learned, the browser can, with a push of a button on the UI,take the user in a sequence of the most to least favorite sub-pages ofthe index page. As seen in FIG. 9, first through fourth sub-pages aredisplayed upon demand in a sequence derived by the browsing softwarefrom active and/or passive learning procedures.

For the web pages that use scripts extensively, a multi-subjectsplitting technique can be avoided in favor of providing scrollingassistance through an auto-positioning solution. In the auto-positioningsolution, a plug-in for the browser software can be provided. When theplug-in is invoked, it will analyze the web page currently be browsedand produce proper sub-pages according to the target size of the displayon the small form factor device. Then the browsing view will be switchedto a thumbnail view which is similar with the local index page in themulti-subject splitting solution. Clicking on the thumbnail will switchback to the browsing view and the focus will be on the correspondingsub-page that was selected by the user's input ‘click’ function.

Exemplary Computer Environment

The embodiments described above can be implemented in connection withany suitable computer environment. Aspects of the various embodimentscan, for example, be implemented, in connection with server computers,client computers/devices including small form factor devices, or bothserver computers and client computers/devices. As but one exampledescribing certain components of an exemplary computing system, considerFIG. 10.

FIG. 10 illustrates an example of a suitable computing environment 800.It is to be appreciated that computing environment 800 is only oneexample of a suitable computing environment and is not intended tosuggest any limitation as to the scope of use or functionality of theinventive embodiments. Neither should the computing environment 800 beinterpreted as having any dependency or requirement relating to any oneor combination of components illustrated in the exemplary computingenvironment 800.

The inventive techniques can be operational with numerous other generalpurpose or special purpose computing system environments orconfigurations. Examples of well known computing systems, environments,and/or configurations that may be suitable for use with the inventivetechniques include, but are not limited to, personal computers, servercomputers, thin clients, thick clients, hand-held or laptop devices,multiprocessor systems, microprocessor-based systems, set top boxes,programmable consumer electronics, network PCs, minicomputers, mainframecomputers, distributed computing environments that include any of theabove systems or devices, and the like.

In certain implementations, the inventive techniques can be described inthe general context of computer-executable instructions, such as programmodules, being executed by a computer. Generally, program modulesinclude routines, programs, objects, components, data structures, etc.that perform particular tasks or implement particular abstract datatypes. Implementations may also be practiced in distributed computingenvironments where tasks are performed by remote processing devices thatare linked through a communications network. In a distributed computingenvironment, program modules may be located in both local and remotecomputer storage media including memory storage devices.

In accordance with the illustrated example embodiment of FIG. 10computing system 800 is shown comprising one or more processors orprocessing units 802, a system memory 804, and a bus 806 that couplesvarious system components including the system memory 804 to theprocessor 802.

Bus 806 is intended to represent one or more of any of several types ofbus structures, including a memory bus or memory controller, aperipheral bus, an accelerated graphics port, and a processor or localbus using any of a variety of bus architectures. By way of example, andnot limitation, such architectures include Industry StandardArchitecture (ISA) bus, Micro Channel Architecture (MCA) bus, EnhancedISA (EISA) bus, Video Electronics Standards Association (VESA) localbus, and Peripheral Component Interconnects (PCI) buss also known asMezzanine bus.

Computer 800 typically includes a variety of computer readable media.Such media may be any available media that is locally and/or remotelyaccessible by computer 800, and it includes both volatile andnon-volatile media, removable and non-removable media.

In FIG. 10, the system memory 804 includes computer readable media inthe form of volatile, such as random access memory (RAM) 810, and/ornon-volatile memory, such as read only memory (ROM) 808. A basicinput/output system (BIOS) 812, containing the basic routines that helpto transfer information between elements within computer 800, such asduring start-up, is stored in ROM 808. RAM 810 typically contains dataand/or program modules that are immediately accessible to and/orpresently be operated on by processing unit(s) 802.

Computer 800 may further include other removable/non-removable,volatile/non-volatile computer storage media. By way of example only,FIG. 10 illustrates a hard disk drive 828 for reading from and writingto a non-removable, non-volatile magnetic media (not shown and typicallycalled a “hard drive”), a magnetic disk drive 830 for reading from andwriting to a removable non-volatile magnetic disk 832 (e.g., a “floppydisk”), and an optical disk drive 834 for reading from or writing to aremovable, non-volatile optical disk 836 such as a CD-ROM, DVD-ROM orother optical media. The hard disk drive 828, magnetic disk drive 830,and optical disk drive 834 are each connected to bus 806 by one or moreinterfaces 826.

The drives and their associated computer-readable media providenonvolatile storage of computer readable instructions, data structures,program modules, and other data for computer 800. Although the exemplaryenvironment described herein employs a hard disk 828, a removablemagnetic disk 832 and a removable optical disk 836, it should beappreciated by those skilled in the art that other types of computerreadable media which can store data that is accessible by a computer,such as magnetic cassettes, flash memory cards, digital video disks,random access memories (RAMs), read only memories (ROM), and the like,may also be used in the exemplary operating environment.

A number of program modules may be stored on the hard disk 828, magneticdisk 832, optical disk 836, ROM 808, or RAM 810, including, by way ofexample, and not limitation, an operating system 814, one or moreapplication programs 816 (e.g., multimedia application program 824),other program modules 818, and program data 820. Some of the applicationprograms can be configured to present a user interface (UI) that isconfigured to allow a user to interact with the application program insome manner using some type of input device. This UI is typically avisual display that is capable of receiving user input and processingthat user input in some way. Such a UT may, for example, comprise one ormore buttons or controls that can be clicked on by a user.

Continuing with FIG. 10, a user may enter commands and information intocomputer 800 through input devices such as keyboard 838 and pointingdevice 840 (such as a “mouse”). Other input devices may include aaudio/video input device(s) 853, a microphone, joystick, game pad,satellite dish, serial port, scanner, or the like (not shown). These andother input devices are connected to the processing unit(s) 802 throughinput interface(s) 842 that is coupled to bus 806, but may be connectedby other interface and bus structures, such as a parallel port, gameport, or a universal serial bus (USB).

A monitor 856 or other type of display device is also connected to bus806 via an interface, such as a video adapter 844. In addition to themonitor, personal computers typically include other peripheral outputdevices (not shown), such as speakers and printers, which may beconnected through output peripheral interface 846.

Computer 800 may operate in a networked environment using logicalconnections to one or more remote computers, such as a remote computer850. Remote computer 850 may include many or all of the elements andfeatures described herein relative to computer 800.

As shown in FIG. 10, computing system 800 can be communicatively coupledto remote devices (e.g., remote computer 850) through a local areanetwork (LAN) 851 and a general wide area network (WAN) 852. Suchnetworking environments are commonplace in offices, enterprise-widecomputer networks, intranets, and the Internet.

When used in a LAN networking environment, the computer 800 is connectedto LAN 851 through a suitable network interface or adapter 848. Whenused in a WAN networking environment, the computer 800 typicallyincludes a modem 854 or other means for establishing communications overthe WAN 852. The modem 854, which may be internal or external, may beconnected to the system bus 806 via the user input interface 842, orother appropriate mechanism.

In a networked environment, program modules depicted relative to thepersonal computer 800, or portions thereof, may be stored in a remotememory storage device. By way of example, and not limitation, FIG. 10illustrates remote application programs 816 as residing on a memorydevice of remote computer 850. It will be appreciated that the networkconnections shown and described are exemplary and other means ofestablishing a communications link between the computers may be used.

Conclusions

Implementations include a web page adaptation method of pagepartitioning and bi-level browsing convention to improve the browsingexperiences on small form factor devices. The web page adaptation methodincludes the two stages of analysis of the web page to obtain itsstructure and page splitting. In the analysis stage, a hierarchy iscreated to represent the web page's semantic and visual structure.According to this hierarchy and the screen size of the small form factordevice browsing the web page, appropriate blocks are selected assub-pages. After sub-page generation, an image index page with blockmarking is created to assist navigation. A bi-level browsing conventionfirst displays to a user a thumbnail image of the index page havingthereon a plurality of icons representing sub-pages. Then user can clickon one of the sub-page icons to browse an enlarged image of thecorresponding sub-page.

Although the invention has been described in language specific tostructural features and/or methodological steps, it is to be understoodthat the invention defined in the appended claims is not necessarilylimited to the specific features or steps described. Rather, thespecific features and steps are disclosed as preferred forms ofimplementing the claimed invention.

1. One or more computer-readable storage media having computer-readableinstructions thereon which, when executed by one or more processors,cause the one or more processors to perform a method comprising:extracting high level structure information about a web page usingmarkup language tag tree selection rules to define high levelboundaries; extracting low level structure information within each highlevel structure information by: identifying explicit visual boundariesfrom the properties of one or more tags of the markup language tag treeby clustering the one or more tags in a pattern detection algorithmenabling the detection of one or more regions within the high levelstructure information; identifying visual units by boundary detectionfrom the markup language tag tree corresponding to each high levelstructure information; and projecting each visual unit perpendicularlyto an axis to identify implicit boundaries between the visual units;storing the high level boundaries, the implicit boundaries, and theextracted high and low level structure information of the web page usingan annotation mechanism, and for a predetermined display screen having awidth, identifying a plurality of sub-pages of the web page using thehigh level boundaries, the implicit boundaries, and the extracted highand low level structure information of the web page, wherein eachsub-page has a width not greater than the width of the predetermineddisplay screen; forming a thumbnail image of the web page havingpartitions corresponding to the one or more sub-pages; forming ahyperlink to each sub-page from a corresponding partition of thethumbnail image of the web page; and storing the sub-pages, thethumbnail image, and the hyperlinks using the annotation mechanism. 2.The one or more computer-readable storage media as defined in claim 1,wherein the identifying visual units further comprises: collecting basicnodes from the markup language tag tree corresponding to each said highlevel structure information; classifying the collected basic nodes;grouping similar classifications of the collected basic nodes intosymbol strings; detecting and merging adjacent similar patterns in thesymbol strings of the classified collected basic nodes to form newsymbol strings; and determining each non-blank symbol in each remainingsymbol string to be one identified visual unit for implicit boundarydetection.
 3. The one or more computer-readable storage media as definedin claim 1, wherein the method further comprises, for contents of eachsaid sub-page, extracting any style information from the markup languagetag tree of the web page for inclusion in the sub-page.
 4. A methodcomprising: using a markup language tag tree of the web page to extractregions of the web page including a header, a footer, left and rightside bar regions, and one or more body regions encompassed by the headerregion, the footer region, the left side bar region, and the right sidebar region; identifying visual boundaries within each region by:arranging the properties of the tags of the markup language tag tree byclustering the tags in a pattern detection algorithm enabling thedetection of the regions of the web page; projecting, normal to an axis,each shape represented by one or more semantic units of the tags of themarkup language tag tree in each region; determining the additionalvisual boundaries from projection values on the axis; and for apredetermined display screen, identifying a plurality of sub-pages ofthe web page using the identified visual boundaries and the regions,where each sub-page has a width not greater than the width of thepredetermined display screen; forming a thumbnail image of the web pagehaving partitions corresponding to the one or more sub-pages; forming ahyperlink to each sub-page from a corresponding partition of thethumbnail image of the web page; and storing the sub-pages, thethumbnail image, and the hyperlinks using an annotation mechanism. 5.The method as defined in claim 4, further comprising, for the contentseach sub-page, extracting any style information from the markup languagetag tree of the web page for inclusion in the sub-page.
 6. One or morecomputer-readable storage media having computer-readable instructionsthereon which, when executed by one or more processors, cause the one ormore processors to implement the method of claim
 4. 7. A methodcomprising: analyzing a markup language tag tree of a web page toidentify: peripheral regions of the web page including header, footer,left, and right regions; and one or more body regions adjacent to atleast one peripheral region; within the markup language tag tree thatdefines each peripheral and body region: identifying visual boundariesgiven in the properties of the tags of the markup language tag tree byclustering the tags of the markup tag tree in a pattern detectionalgorithm enabling the detection of the peripheral regions of the webpage and the one or more body regions of the web page; and identifyingblank areas by: analyzing one or more functions on the basis of a layoutstructure of each function by: configuring each function into arectangle; projecting each rectangle normally onto each of perpendicularaxes; determining one or more separators that are each normal to theaxes as a function of a sum of projections on each axis where thequantity of the projections is less than a predetermined threshold; andfor a predetermined width of a display screen, identifying a pluralityof sub-pages of the web page each having a width not greater than thepredetermined width of the display screen and using: the peripheralregions of the web page including header, footer, left, and rightregions; the one or more body regions adjacent to at least oneperipheral region; the visual boundaries identified in the properties ofthe tags of the markup language tag tree; the one more separators; andforming a thumbnail image of the web page having partitionscorresponding to the one or more sub-pages; forming a hyperlink to eachsub-page from a corresponding partition of the thumbnail image of theweb page; and storing the sub-pages, the thumbnail image, and thehyperlinks using an annotation mechanism.
 8. The method as defined inclaim 7, further comprising, for the contents each sub-page, extractingany style information from the markup language tag tree of the web pagefor inclusion in the sub-page.
 9. One or more computer-readable storagemedia having computer-readable instructions thereon which, when executedby one or more processors, cause the one or more processors to implementthe method of claim 7.